You have probably already installed and activated Unity. Where you should look for the latest Unity version and license might be obvious. However, I've noticed lots of questions online about where you can get Unity for free, and so I decided to cover this subject. If you feel that this step is obsolete for you, skip this part.
The best place to download your Unity copy from is, of course, Unity's official website: http://unity3d.com/unity/download.
In this book, we will be covering Unity Version 5.0 and higher. We need to download the latest version of Unity and install it with all components ticked. It's a good idea to install Unity with the example project. The Unity Example project (the Angry Bots game) is there for us to play with, experiment, and learn.
The easiest way to obtain a Unity license is by simply launching Unity for the first time. The following steps will guide you to do so:
You are now all set with the latest version of Unity and a free license!